2. Field of the Invention
The invention relates to devices for treating fiber webs and in particular to vibration-damped rolls for producing and treating paper webs.
2. Description of Related Technology
A roll for the production or treatment of fiber webs such as paper webs is known from DE 36 38 070 (corresponding to Schiel, U.S. Pat. No. 5,081,759 issued Jan. 21, 1992). Such a roll has a fixed central axis and a roll shell which rotates around the central axis. The central axis has liquid and gas-filled chambers which cooperate with each other and provide vibration damping for the entire roll.
Although the teachings disclosed in DE 36 38 070 provide means for damping vibrations, the configurations of the roll damping members described therein are complicated and, as a result, cost-intensive. Furthermore, the roll disclosed in DE 36 38 070 in some circumstances does not sufficiently provide vibration damping.
For example, it has been found that providing both chambers of the roll with damping members as shown in FIGS. 1-3 of DE 36 38 070 may be undesirable. Also, the position of the damping members in chambers 7 and 8 as shown in these figures does not provide optimum damping because certain capillary characteristics must be at least approximately maintained.